Co-fermentation of waste activated sludge and molasses for targeted butyrate-rich SCFA production: Deciphering the dual regulatory role of melanoidins and microbial carbon rewiring

Waste activated sludge (WAS) valorization faces critical bottlenecks of low hydrolysis efficiency, limiting short-chain fatty acids (SCFAs) recovery. This study pioneers co-fermentation of WAS with waste molasses at optimized volatile solids (VS) ratios (1:1, 2:1, 1:2) to reprogram carbon metabolism and microbial functionality.